HTC Tattoo Sync - duplicate entries

Hi, I've recently got a a Tattoo and it is mostly fine (apart from the riduculously hard to remove battery cover!).

But the thing that is driving me nuts is how unstable HTC Sync is..........I have uninstalled, re-installed on the PC and phone and had to delete all contacts on the phone once to "cleanse" and still every time I go to sync my calendar and contacts something goes wrong........duplicates contacts and calendar entries in the phone and and on my PC!!!!!

My work phone is windows and active sync is a dream compared to this!

Is anyone else having the same problems and does anyone have a solution or is this software just plain rubbish??